Bony substitutes based on calcium phosphate particles and a biological adhesive are known from the state of the art.
Thus, G. Daculsi et al. have described in Ann. Oto. Rhino. Laryngol. 101:1992 the effectiveness of a calcium phosphate two-phase microporous composition for obliterating the mastoid cavity.
The same authors have also reported the effectiveness of a two-phase calcium phosphate macroporous composition for surgical repair of long bones (Journal of Biomedical Materials Research, Vol. 24, 379-396) and in vertebral arthrodeses (Clinical Orthopaedics and Related Research, 248, 1989, 169-175).
The usefulness of calcium phosphates in odontology has been demonstrated in a number of articles: A. Jean et al. in Cells and materials 1993; 3: 193-200. "Pulpal response to calcium phosphate materials. In vivo study of Calcium Phosphate materials in Endodontics"; B. Aliot-Licht et al. in Arch. Oral Biol. 1994; 39: 481-489 "Comparative effect of calcium hydroxide and hydroxyapatite on the cellular activity of human pulpal fibroblasts. An in vivo approach."
Furthermore, JP 3 011 006 describes a cement for hard tissues including an inorganic phase consisting of at least 60% of alpha tricalcium phosphate and of hydroxy-apatite and/or a calcium monophosphate, and a liquid phase including carboxymethyl cellulose.
However, such a composition exhibits the disadvantage, due to the excessive solubility of .alpha. tricalcium phosphate, of not being sufficiently stable to permit a process of resorption/substitution of the hard tissue. Furthermore, such a composition is liable to give rise to detrimental inflammatory processes. Furthermore, this mixture constitutes a calcium ionomer which is not suitable for injection after a few minutes, due to hardening of the mixture as soon as it is made up. This combination exhibits a double instability, a contraction in volume with release of water after several days and, above all, a drop in viscosity after sterilization of the mixture in the autoclave. It does not make it possible to produce a material which is "ready for use", sterile and injectable.